Re: Interresting difference in Normal-Returns/Expression-Functions and Extended-Returns.

[egilhh <egilhovik@hotmail.com>]

On Tuesday, April 23, 2013 7:57:56 PM UTC+2, Adam Beneschan wrote:
> On Tuesday, April 23, 2013 9:52:04 AM UTC-7, Simon Wright wrote:
> 
>  
> I don't see a language reason for that.  The tasks are all created with allocators, and the type of the allocator alone should determine what master the tasks depend on--not a block declaring an array that contains the access objects.  If it's true that the block doesn't exit until all the tasks created by allocators have completed, then it's probably a GNAT bug.  I'd need to study it more carefully to make sure, though.  There may be some relevant language rules I'm missing, or something else I'm missing.
> 

I've been reading up on the accessibility rules (RM 3.10.2), and the rules
for functions returning anonymous access types have changed from 2005 to 2012.
In my understanding, 2012 now requires the block to wait:

RM 3.10.2(10.1/3): "The accessibility level of the result of a function call is
that of the master of the function call, which is determined by the point of
call as follows:"

RM 3.10.2(10.2/3): "If the result is used (in its entirety) to directly
initialize part of an object, the master is that of the object being
initialized. In the case where the initialized object is a coextension (see
below) that becomes a coextension of another object, the master is that of the
eventual object to which the coextension will be transferred."

RM 3.10.2(10.7/3): "In the case of a call to a function whose result type
is an anonymous access type, the accessibility level of the type of the result
of the function call is also determined by the point of call as described
above"),

whereas 2005 permitted the other behavior. (A language lawyer is needed to
confirm this)


-- 
~egilhh